Rotary and linear actuators are used in a wide variety of applications. A common configuration of a rotary actuator begins with a motion controllable electric motor. A gear reducer is added to the motor to increase torque output and improve system stability. Another common design of an actuator (for linear output motion) includes a motor, such as an electric motor that generates rotational motion at its output shaft. A linear actuator converts that motion into linear motion that is then applied to the system's load. In this example, the output motion (linear) is applied such that the load is moved along the same or similar path as the linear actuator's output shaft.
Sometimes particular applications require additional functionality. In order to provide this functionality, a customized design may be required that is specifically tailored to the application. Such custom designed actuators can be expensive, require considerable design time, and add a significant amount of time to produce. In some cases, there may not be a suitable design that provides the functionality required by the application.